1960—2012年河西走廊中部沙尘暴空间分布特征和变化规律

Spatial Distribution and Variation of Sandstorms in the Central Hexi Corridor during 1960-2012

利用6个常规气象站1960—2012年的沙尘暴观测资料,分析了河西走廊中部近53年沙尘暴日数的年代际、年际、季节、各月变化和空间分布,并用Mann-Kendall检验法检验河西走廊中部沙尘暴序列是否存在突变现象;在分析沙尘暴变化规律的基础上,建立了河西走廊中部沙尘暴日数的均生函数预测模型。结果表明:该地区1960—2012年的沙尘暴日数以11.75d/10a的倾向率递减;20世纪60年代至80年代中期为沙尘暴多发期,进入80年代末沙尘暴日数开始明显下降;20世纪70年代最多,60年代次之,80年代到90年代中期逐渐递减,从1997年开始到2004年又处于逐渐上升的趋势,突出年份是2001年,此年共21d发生了沙尘暴天气;20世纪80年代河西走廊中部沙尘暴日数有一明显减少的突变,具体时间是1983年。与沙尘暴日数相关性最强的是年平均气温,呈显著负相关,其次是春季平均气温、冬季蒸发量和春季蒸发量,有5个站点的沙尘暴日数与春季平均气温呈显著负相关、与冬季蒸发量和春季蒸发量呈显著正相关,有3个站点的沙尘暴日数与冬季平均气温和冬季降水量呈显著负相关。据预测,2013—2032年河西走廊中部沙尘暴日数将呈继续减少趋势。

Using the sandstorm days data from6 meteorological stations in central Hexi Corridor from1960to2012,the inter-decadal,inter-annual,seasonal,monthly variation and spatial variation of the sandstorm days were analyzed.Whether there were mutations in the sandstorm sequence was tested by Mann-Kendall test.A mean generating function model for the prediction of sandstorm days in central Hexi Corridor was established based on analysis of the change rule of sandstorms.The results showed that the sandstorm days in this area presented a decline tendency at a rate of 11.75 d/10a from1960 to 2012.It was a high frequency period of sandstorms from1960s to the mid-1980s.It began to decline obviously during the late 1980s.The first many sandstorm days were in 1970s,second in 1960s,and it began to decline gradually from1980s to the mid-1990s,and then it showed an ascending tendency from1997 to 2004.The outstanding year was 2001 and a total of sandstorm weather was 21 d in this year.The sandstorm days in central Hexi Corridor had an obviously reduced mutation since 1983.There was a significant negative correlation between the annual average temperature and sandstorm days.It was the most relevant one,followed by the spring average temperature,the winter evaporation and spring evaporation.5 meteorological stations' sandstorm days was negatively correlated with the spring average temperature,and positively correlated with the winter evaporation and spring evaporation.3 meteorological stations' sandstorm days was negatively correlated with the winter average temperature and winter precipitation.It was predicted that the sandstorm days will be in a decreasing trend in the next 20 years in central Hexi Corridor.